The present invention relates to pressurized feed systems to treat water and, more particularly, relates to introducing CO2 into the water to reduce the pH.
Raw water may be treated by any number of ways to obtain a final treated water product. However, the final treated water product may have a pH level unsuitable for commercial or consumer requirements. Typically, a final treated water product requires a pH level of less than 9. One method for lowering the pH level in water is to inject CO2 into the water by a direct gas feed system. The CO2 is passed through a diffusion system in a recarbonated basin. This diffusion system is commonly referred to as a bubbler. Another method for injecting carbon dioxide into water is to aspirate the carbon dioxide with a venturi. An apparatus using a venturi is sometimes also referred to as a diffuser.
In either method of introducing CO2 into water, the CO2 is introduced into a carrier solution to form a carbonic acid solution. To keep the CO2 in solution and prevent the formation of gas bubbles in the system, the carbonic acid solution is maintained at an elevated pressure. Diffusers are engineered to maintain the system pressure and to distribute the carbonic acid solution into the water being treated. As the pressurized carbonic acid solution is introduced into the water being treated, the CO2 expands and is released and mixed into the stream of water.
An example of a known diffuser is disclosed in my U.S. Pat. No. 5,487,835, the entire disclosure of which is incorporated herein by reference. In my ""835 patent, the diffuser 71 has three rectangular sides defining a triangular prismatic structure. The diffuser 71 is inserted normal to the direction of flow of the water stream. The carbonic acid solution is passed through one end of the diffuser 71. While the carbonic acid solution is within the diffuser 71, the diffuser 71 maintains the elevated pressure of the carrier solution forcing the formation of carbonic acid and excess CO2, if any, to remain in the carbonic acid solution.
The diffuser 71 has a plurality of outlet holes on two of the rectangular sides. The plurality of holes face upstream while the third rectangular side faces down stream. The passing of the carbonic acid solution through the plurality of holes forces the CO2, if any, to be released into the stream of water to reduce the pH. The downstream positioning of the third side without the holes creates a vortex in the stream of water which creates additional mixing.
The present invention provides an apparatus for adjusting the pH of water using a carbonic acid solution. The diffuser of the present invention maintains the system back pressure when processing the carbonic acid solution and dispenses the CO2, if any, to adjust the pH of the water being treated.
In one embodiment of the present invention, the diffuser includes an injector for injecting the carbonic acid solution into a receiver tank. Centrally located within the interior of the receiver tank is a driven impeller. The injector directs the carbonic acid solution towards the impeller. The rotation of the impeller causes the carbonic acid solution and the water within the receiver tank to commingle.
According to another embodiment of the invention, a diffuser of the present invention includes an annular cylinder with a hollow formed therein. A solution inlet permits carbonic acid solution into the annular cylinder. The annular cylinder defines an interior path leading from the inlet, through the hollow, and back to the inlet. A plurality of outlet holes are formed in an upper side of the annular cylinder. The outlet holes permit the carbonic acid solution to flow from the hollow to the exterior of the annular cylinder.
In still another embodiment of the present invention, a diffuser of the present invention includes an elongated body having a hollow therethrough. One end of the elongated body includes an end plate over the hollow. The end plate defines an obround outlet for permitting carbonic acid solution to pass into the water to be treated. The obround outlet is shaped to direct the solution in a particular manner.
In yet another embodiment of the present invention, a diffuser of the present invention includes a pair of laterally displaced nozzles. The pair of nozzles extend into a mixing cylinder and are fixed in a stationary position. The nozzles are oppositely-oriented relative to one another to direct carbonic acid solution passing through each of the nozzles in opposite directions which causes the water and the solution to circulate in the mixing cylinder.